Conventional electronic device manufacturing systems may include one or more process chambers. In some systems, the one or more process chambers may be arranged around a mainframe housing having a transfer chamber and one or more load lock chambers. These systems may employ one or more process chambers that may perform a process on a substrate (e.g., a wafer) inserted into the process chamber. Processing may include a deposition, etch, cleaning or other process. During processing, wafers may rest on a pedestal, platen or other support and may be heated at one or more times during the process. Heating may be provided by resistive heaters in some embodiments. In other embodiments, heating may be provided by exposing the substrate to plasma. In the plasma case, the pedestal (sometimes referred to as an “electro-static chuck” or “platen”) may include cooling (e.g., cooling passages in the platen base) and may include other electrical elements as well. It should be recognized, however, that even small variations in temperature across the substrate may cause differential processing (e.g., differential etch, deposition, cleaning or other processing) thereof. Thus, improved precision of temperature control during processing is desired.
Accordingly, systems, apparatus, and methods having improved substrate temperature control in the processing of substrates are desired.